Are Americans missing an opportunity to prevent dementia?

Lawmakers signed the National Alzheimer’s Project Act (NAPA) into law on January 4, 2011. The law requires the United States Department of Health and Human Services (HHS) to achieve several goals, including:

• Establishing a National Alzheimer’s Project to create and maintain a national plan to overcome this disease,
• Coordinating research efforts across all federal agencies, and
• Coordinating on a global level to help combat Alzheimer’s disease.

The 2021 National Plan to Address Alzheimer’s Disease (National Plan) also recognized the importance of the goal to reduce the risk for Alzheimer disease and related dementias (ADRD).

Has NAPA achieved these goals? The efforts are a work in progress. The law defines Alzheimer’s to include Alzheimer’s disease, as well as Alzheimer’s disease-related dementias.

What are modifiable risk factors?

In 2019, The Centers for Disease Control and Prevention (CDC) gathered data from 162,000 adults over the age of 45 and found that over 10% of adults experience some form of subjective cognitive decline (SCD). This is important as SCD is an early indicator of the risk of future Alzheimer’s. The CDC has thus called on the nation to take steps to help the anticipated swell in an older adult population that could experience these issues by addressing modifiable risk factors.

Modifiable risk factors are essentially those that can increase the risk of an individual developing a disease, in this case, Alzheimer’s. These risk factors are referred to within the scientific community as modifiable because the individual, in theory, can make changes that will directly impact the factor at issue.

The CDC reported that among adults aged ≥45 years, the most common potentially modifiable risk factors for ADRD were high blood pressure and insufficient aerobic exercise/ not meeting the aerobic physical activity guideline, both of which were found in nearly one half of adults with subjective cognitive decline (SCD).

Medical risk factors include:

• High Blood Pressure. 50% of the respondents reported the presence of high blood pressure.
• Insufficient Aerobic Exercise. 50% of the respondents failed to achieve recommended aerobic exercise recommendations. The American Heart Association (AHA, 2016) currently recommends 150 minutes of moderate physical activity per week.
• Obesity. 35% of people with SCD were obese.
• Diabetes. 19% of people with SCD were diabetic.
• Depression. 18% of people with SCD suffered from depression.

Lifestyle Risk Factors include:

• Smoking. Smoking negatively affects circulation throughout the body including the blood supply to the brain. Small microvascular infarcts lead to dementia. Smoking was found in 15% of people with SCD.
• Alcohol. Alcohol has a direct neurotoxic effect and, in a person already at risk for SCD, alcohol consumption accelerates cognitive decline. Alcohol was a contributing factor in 10% of people with SCD.

Adults over 45 years of age with subjective cognitive decline (SCD) were more likely to report four or more risk factors compared with those without SCD (34.3% versus 13.1%). Prevalence of SCD increased from 3.9% among adults with no risk factors to 25.0% among those with four or more risk factors.

Stemming the progression of dementia

Recently, cognitive training has been used to help prevent progressing dementia. The evidence for cognitive training’s effect on SCD is encouraging but inconclusive.

While there is no cure for Alzheimer’s and SCD, there are actions one can take to reduce the risk of developing dementia. Medical management of high blood pressure and diabetes, physical exercise as recommended by the AHA, and losing weight can all lessen the risk, as can stopping smoking and alcohol consumption. Preventing and delaying the progression of dementia is possible by reducing these risk factors and the negative effects on brain function they cause.